Pheochromocytomas and Paragangliomas

Evolution of metabolic disorders after resection of pheochromocytomas and paragangliomas: a single-center study

Background and aims

Pheochromocytomas and paragangliomas are rare neuroendocrine tumors, responsible for inappropriate secretion of catecholamines, inducing metabolic disorders, increasing basal metabolic rate. Our study aimed to analyze the metabolic profile pre- and post-operatively in patients undergoing surgery for pheochromocytomas and paragangliomas and additionally to determine the predictive factors of metabolic remission.

Methods

This was a retrospective, unicentric, descriptive, and analytical study with a duration of 9 years. It includes data from 35 patients followed up for pheochromocytoma or paraganglioma in the Endocrinology-Diabetology and Nutrition Department of a University Hospital Center. All patients underwent surgery for pheochromocytoma or paraganglioma.

Results

Among the 35 patients, 51.4% of the patients with pheochromocytomas had diabetes mellitus, and 42.8% had dyslipidemia. We found that high levels of catecholamines were associated with the onset of diabetes. We also noted that patients with a long history of the disease were statistically at greater risk of developing dyslipidemia. After surgery, the body mass index of our patients had statistically increased, and 50% of patients experienced resolution or improvement of their diabetes. Improvement of dyslipidemia was observed in 53% of patients. We also found that the percentage of dyslipidemia was higher in patients who did not resolve their diabetes.

Conclusion

Diabetes mellitus and dyslipidemia are metabolic complications that must be investigated in patients with pheochromocytoma. Post-operative monitoring of body mass index and changes in glycemic and lipid levels is essential to adapt therapeutic management.

SDHB-Associated Pheochromocytomas: What is Their Clinical Behavior?

INTRODUCTION

Germline pathogenic variants in succinate dehydrogenase subunit B (SDHB) cause paraganglioma/pheochromocytoma syndrome type 4 (PGL-4). SDHB-associated pheochromocytomas (PCC) are thought to be rare and little data exist about their clinical behavior.

PATIENTS AND METHODS

Retrospective review of patients treated (1993-2023) at a tertiary cancer center for SDHB-associated PCC. Clinical and demographic variables were retrieved to characterize disease-free survival, disease progression, and overall survival.

RESULTS

In total, 90 SDHB-carriers were identified, 18% had PCC (n = 16). Median age at diagnosis of was 40 (19-76) years, 50% (n = 8) of patients were male, 25% (n = 4) had distant metastasis (DM) at diagnosis, and 13% (n = 2) had synchronous PGL. No patients had bilateral disease, and 94% of patients underwent surgery as initial treatment with a curative intent in 75%. Overall, 64% of patients underwent open resection. Recurrence occurred in 77% of patients (n = 10), 75% in minimally invasive surgery (MIS) versus 77% open, p = 0.63. Bone was the most common site of DM (100%, n = 13). Metaidobenzyleguanidine (MIBG) imaging was performed in 69% of patients, 91% of which were positive. Median time from surgery until recurrence was 36 months (1-295 months). Radiation therapy was the most common adjuvant treatment (44%) followed by Iobenguane I-131 (31%) and systemic therapy (31%). Median follow-up time was 56 months (1-408 months). Overall, 33% of patients were alive, 19% of patients were disease-free, and 50% of the patients with DM had stable disease at last follow-up.

CONCLUSIONS

Overall, 18% of germline SDHB mutation-carriers were diagnosed with PCC, all of which were unilateral. SDHB-associated PCC was associated with advanced and recalcitrant disease and was often MIBG positive. More studies are needed to better understand the clinical behavior of PCC in PGL-4.

Metabolomics and proteomics in pheochromocytoma and paraganglioma: Translating biochemistry and biology to bedside

The complexity of omes - the key cellular ensembles (genome and epigenome, transcriptome, proteome, and metabolome) - is becoming increasingly understood in terms of big-data analysis, the omics. Amongst these, proteomics provides a global description of quantitative and qualitative alterations of protein expression (or protein abundance in body fluids) in response to physiologic or pathologic processes while metabolomics offers a functional portrait of the physiological state by quantifying metabolite abundances in biological samples. Here, we summarize how different techniques of proteomic and metabolic analysis can be used to define key biochemical characteristics of pheochromocytomas/paragangliomas (PPGL). The significance of omics in understanding features of PPGL biology that might translate to improved diagnosis and treatment will be highlighted.

Multiple Endocrine Neoplasia with Multiple PGLs in Two Boxer Dogs: Morphological Features, Immunohistochemical Profile and SDHD Gene Mutation Screening

This study aimed to describe the gross and histological features of multiple endocrine and non-endocrine neoplasia, including multiple PGLs found in two Boxer dogs. Additionally, the identified PGLs were immunohistochemically evaluated, and the subunits 2, 3, and 4 of the SDHD gene were screened for possible mutations. The tumors identified include aortic and carotid body PGLs, thyroid follicular-compact carcinoma, and subcutaneous lipomas. One case also had a Leydig cell tumor and adrenal cortex hyperplasia, while the other had H-type pancreatic carcinoma. Three out of 4 PGLs appeared benign, but one aortic body tumor showed malignant features with neoplastic emboli at its edge. Immunohistochemical analysis confirmed the neuroendocrine origin of all PGLs, with positive staining for Chromogranin A, NSE, and variable positivity for S100. No somatic mutations were found in exons 2, 3, and 4 of the SDHD gene in any of the evaluated PGLs. The absence of mutations in the evaluated SDHD gene subunits suggests the involvement of other genetic factors or pathways in the development of these tumors, warranting further investigation in this field.

Multidisciplinary management of chylous ascites following resection of a retroperitoneal, functional Paraganglioma

Extra-adrenal, functional paraganglioma, if not medically controlled, requires early surgical resection. This can often be challenging when found in a retroperitoneal location, where resections are prone to lymphatic disruption and chyle leaks. Chylous ascites carry a significant risk of protein and caloric malnutrition, dehydration, and even mortality given the nutrient-rich characteristic of lost lymphatic fluid. Dietary modification involving minimal fat intake is often frontline conservative treatment, however, prolonged, heavy-volume chylous ascites will require advanced medical and surgical intervention. This case illustrates the difficulties, complexities, and solutions with multidisciplinary management of lymphatic leakage following resection of a functional, retroperitoneal paraganglioma.

Near-fatal pheochromocytoma crisis after beta-blocker and tumour haemorrhage

Pheochromocytomas are rare neuroendocrine tumors characterised by the secretion of catecholamines and their metabolites. While some patients may be asymptomatic, they can also present with various symptoms including hypertensive crisis, headaches, palpitations, diaphoresis or other signs of catecholamine toxicity. Adrenal haemorrhage, though rare, is a potentially fatal complication that is often diagnosed during autopsy. In all patients with suspected pheochromocytoma, regardless of whether haemorrhagic conversion has occurred, prompt diagnosis is imperative. Early identification allows for the timely initiation of treatment, preventing potentially life-threatening complications. This case report details the haemorrhagic conversion of an undiagnosed pheochromocytoma in a female patient in her 30s.

Polyamine Pathway Inhibitor DENSPM Suppresses Lipid Metabolism in Pheochromocytoma Cell Line

Pheochromocytomas (PCCs) are tumors arising from chromaffin cells in the adrenal medulla, and paragangliomas (PGLs) are tumors derived from extra-adrenal sympathetic or parasympathetic paraganglia; these tumors are collectively referred to as PPGL cancer. Treatment for PPGL primarily involves surgical removal of the tumor, and only limited options are available for treatment of the disease once it becomes metastatic. Human carriers of the heterozygous mutations in the succinate dehydrogenase subunit B (SDHB) gene are susceptible to the development of PPGL. A physiologically relevant PCC patient-derived cell line hPheo1 was developed, and SDHB_KD cells carrying a stable short hairpin knockdown of SDHB were derived from it. An untargeted metabolomic approach uncovered an overactive polyamine pathway in the SDHB_KD cells that was subsequently fully validated in a large set of human SDHB-mutant PPGL tumor samples. We previously reported that treatment with the polyamine metabolism inhibitor N1,N11-diethylnorspermine (DENSPM) drastically inhibited growth of these PCC-derived cells in culture as well as in xenograft mouse models. Here we explored the mechanisms underlying DENSPM action in hPheo1 and SDHB_KD cells. Specifically, by performing an RNAseq analysis, we have identified gene expression changes associated with DENSPM treatment that broadly interfere with all aspects of lipid metabolism, including fatty acid (FA) synthesis, desaturation, and import/uptake. Furthermore, by performing an untargeted lipidomic liquid chromatography-mass spectrometry (LC/MS)-based analysis we uncovered specific groups of lipids that are dramatically reduced as a result of DENSPM treatment. Specifically, the bulk of plasmanyl ether lipid species that have been recently reported as the major determinants of cancer cell fate are notably decreased. In summary, this work suggests an intersection between active polyamine and lipid pathways in PCC cells.

Analysis of clinical and pathological characteristics of retroperitoneal paraganglioma and associated prognostic factors

BACKGROUND AND OBJECTIVES

The aim of this study is to explore the long-term prognostic risk factors associated with patients diagnosed with retroperitoneal paraganglioma (RPGL) and examine their clinical and pathological characteristics.

METHODS

Expressions of biomarkers were identified using immunohistochemistry (IHC) and case databases were retrospectively searched. Survival analysis was performed using Kaplan-Meier and Cox risk regression to identify the factors that influence the postoperative progression-free survival of patients with RPGL.

RESULTS

A total of 105 patients, most of whom had tumors situated in the paraaortic region, and whose average tumor size was 8.6 cm, were enrolled in this study. The average follow-up duration was 51 months, with a mortality rate of 19% and a recurrence and metastasis rate of 41.9%. Tumors were assessed using the modified Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP), and SDHB, S-100, and Ki-67 were stained using IHC in all cases. Out of the total cases examined, negative in SDHB expression were observed in 18.1% of cases, S-100 expression was negative in 36.2% of cases, and endovascular tumor enboluswas present in approximately 25.7% of cases. The results of the univariate analysis indicated that several factors significantly influenced the progression-free survival of patients with PGL as follow: maximum tumor diameter (>5.5 cm), tumor morphological features, tumor grading (modified GAPP score > 6), SDHB negative, S-100 negative, and expression of proliferation index Ki-67 (>3%) (X2 = 4.217-27.420, p < 0.05). The results of the multivariate analysis indicated that negative of S-100 (p = 0.021) and SDHB (p = 0.038), as well as intravascular tumor thrombus (p = 0.047) expression were independent risk factors for progression-free survival in patients.

CONCLUSION

RPGL is characterized by diverse biological features and an elevated susceptibility to both recurrence and metastasis. Both SDHB and S-100 can be employed as traditional IHC indicators to predict the metastatic risk of PGL, whereas the tumor histomorphology-endovascular tumor enbolus assists in determining the metastasis risk of RPGL.

Laparoscopic Resection of Para-Aortic Mass at the Aortic Bifurcation: An Atypical Presentation of a Tailgut Cyst

We review the case of a 43-year-old white male who presented with an enlarging pulsatile mass in the periumbilical region. Diagnostic imaging revealed an 8-cm heterogeneous mass abutting the left iliac artery at the aortic bifurcation. Due to the patient's persistently elevated blood pressure and elevated serum and urine catecholamines, a neuroendocrine tumor was suspected. Laparoscopic resection was performed and was well tolerated. However, the mass was characterized as a tailgut cyst upon pathological examination. This case highlights the utility of laparoscopy for the removal of large para-aortic masses, which can be achieved in a safe fashion by an experienced surgeon. In addition, this case highlights the importance of differential diagnoses in surgeries due to the occurrence of unexpected outcomes.

CT-based radiomics research for discriminating the risk stratification of pheochromocytoma using different machine learning models: a multi-center study

OBJECTIVES

The purpose of this study was to explore and verify the value of various machine learning models in preoperative risk stratification of pheochromocytoma.

METHODS

A total of 155 patients diagnosed with pheochromocytoma through surgical pathology were included in this research (training cohort: n = 105; test cohort: n = 50); the risk stratification scoring system classified a PASS score of < 4 as low risk and a PASS score of ≥ 4 as high risk. From CT images captured during the non-enhanced, arterial, and portal venous phase, radiomic features were extracted. After reducing dimensions and selecting features, Logistic Regression (LR), Extra Trees, and K-Nearest Neighbor (KNN) were utilized to construct the radiomics models. By adopting ROC curve analysis, the optimal radiomics model was selected. Univariate and multivariate logistic regression analyses of clinical radiological features were used to determine the variables and establish a clinical model. The integration of radiomics and clinical features resulted in the creation of a combined model. ROC curve analysis was used to evaluate the performance of the model, while decision curve analysis (DCA) was employed to assess its clinical value.

RESULTS

3591 radiomics features were extracted from the region of interest in unenhanced and dual-phase (arterial and portal venous phase) CT images. 13 radiomics features were deemed to be valuable. The LR model demonstrated the highest prediction efficiency and robustness among the tested radiomics models, with an AUC of 0.877 in the training cohort and 0.857 in the test cohort. Ultimately, the composite of clinical features was utilized to formulate the clinical model. The combined model demonstrated the best discriminative ability (AUC, training cohort: 0.887; test cohort: 0.874). The DCA of the combined model showed the best clinical efficacy.

CONCLUSION

The combined model integrating radiomics and clinical features had an outstanding performance in differentiating the risk of pheochromocytoma and could offer a non-intrusive and effective approach for making clinical decisions.

Multi-disciplinary surgery for simultaneous resection of multiple tumors in a patient with newly diagnosed metastatic pheochromocytoma/paraganglioma

Metastatic pheochromocytoma/paraganglioma (MPP) is a rare endocrine tumor that originates from extra-adrenal chromaffin cells such as the paraganglia cells of sympathetic and parasympathetic nerves. It usually causes multiple solid tumors and exhibits strong aggressiveness with poor prognosis, with a reported 5-year survival rate of less than 50%. Cases of brain and retroperitoneal metastases at the initial diagnosis have not yet been reported. We report a 41-year-old male patient initially diagnosed with MPP in the brain and retroperitoneum who underwent multi-disciplinary collaborative surgery and simultaneous removal of two tumors at our center. Postoperative pathology revealed infiltrative growth of a skull base tumor. The patient chose to receive the tyrosine kinase inhibitor sunitinib as a targeted treatment. A 3-month follow-up after surgery showed that the patient recovered well without signs of metastasis or recurrence. We present multi-disciplinary surgery under similar circumstances for enhanced treatment and postoperative management. The patient demonstrates a favorable prognosis during postoperative follow-up, indicating that simultaneous multidisciplinary surgery may offer greater benefits for MPP patients.

Metastatic paraganglioma presenting with spinal cord compression requiring urgent surgery

We report a rare case of a functional bladder paraganglioma diagnosed in a young man who presented with acute compressive thoracic myelopathy secondary to vertebral metastasis. A histological diagnosis of a metastatic paraganglioma was made following biopsy of a rib lesion. CT revealed a lesion in the inferior wall of the bladder, which demonstrated avid uptake on 68Ga-DOTATATE PET/CT. Serum metanephrine levels were more than 40 times the upper limit of normal. The patient was hypertensive and treatment with doxazosin was initiated. In view of neurological deterioration, he required urgent spinal decompression to preserve neurological function and prevent permanent paraplegia. Despite inadequate alpha-blockade, surgery was successful, and the perioperative course was uneventful. Alpha-blockade was subsequently optimised. Treatment with cyclophosphamide, vincristine and dacarbazine was started but, in view of disease progression, treatment was subsequently changed to sunitinib.

Diabetes Mellitus Secondary to Endocrine Diseases: An Update of Diagnostic and Treatment Particularities

Secondary diabetes mellitus is frequently ignored in specialized literature. In this narrative review, the main endocrinopathies accompanied by increased glycemic values are identified, as well as the mechanisms by which the excess or deficiency of certain hormones impact beta cell function or insulin resistance. The main endocrinopathies (acromegaly, Cushing's syndrome, Basedow-Graves' disease, pheochromocytoma, somatostatinoma and glucagonoma) and their characteristics are described along with the impact of hormone changes on blood sugar, body mass index and other parameters associated with diabetes. The overall information regarding the complex molecular mechanisms that cause the risk of secondary diabetes and metabolic syndrome is of crucial importance in order to prevent the development of the disease and its complications and particularly to reduce the cardiovascular risk of these patients. The purpose of this study is to highlight the particular features of endocrine pathologies accompanied by an increased risk of developing diabetes, in the context of personalized therapeutic decision making. The epidemiological, physiopathological, clinical and therapeutic approaches are presented along with the importance of screening for diabetes in endocrine diseases.

Pheochromocytoma and Hypertrophic Cardiomyopathy Leading to Cardiac Arrest

A 33-year-old female with no known past medical history presented to the hospital for a witnessed cardiac arrest. The patient was emergently intubated and sedated. Further investigation demonstrated an 8.5 cm x 7.6 cm mass in the adrenal region, which was subsequently found to be a pheochromocytoma by biopsy. She was transferred to a tertiary care center for further evaluation. We wish to raise awareness of this condition among clinicians and encourage further research into the connections between pheochromocytoma and further cardiac complications.

Metabolic Characterization and Glyceraldehyde-3-Phosphate Dehydrogenase-Dependent Regulation of Epithelial Sodium Channels in hPheo1 Wild-type and SDHB Knockdown Cells

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors with limited curative treatment options outside of surgical resection. Patients with mutations in succinate dehydrogenase subunit B (SDHB) are at an increased risk of malignant and aggressive disease. As cation channels are associated with tumorigenesis, we studied the expression and activity of cation channels from the Degenerin superfamily in a progenitor cell line derived from a human PCC. hPheo1 wild-type (WT) and SDHB knockdown (KD) cells were studied to investigate whether epithelial sodium channels (ENaC) and acid-sensing ion channels (ASIC) are regulated by the activity of glyceraldehyde-3-phosphate dehydrogenase (GAPDH). First, we performed targeted metabolomic studies and quantified changes in glycolysis pathway intermediates and citric acid cycle intermediates using hPheo1 WT cells and SDHB KD cells. Next, we performed protein biochemistry and electrophysiology studies to characterize the protein expression and activity, respectively, of these ion channels. Our western blot experiments show both ENaC alpha and ASIC1/2 are expressed in both hPheo1 WT and SDHB KD cells, with lower levels of a cleaved 60 kDa form of ENaC in SDHB KD cells. Single-channel patch clamp studies corroborate these results and further indicate channel activity is decreased in SDHB KD cells. Additional experiments showed a more significant decreased membrane potential in SDHB KD cells, which were sensitive to amiloride compared to WT cells. We provide evidence for the differential expression and activity of ENaC and ASIC hybrid channels in hPheo1 WT and SDHB KD cells, providing an important area of investigation in understanding SDHB-related disease.

Applications of spatially resolved omics in the field of endocrine tumors

Endocrine tumors derive from endocrine cells with high heterogeneity in function, structure and embryology, and are characteristic of a marked diversity and tissue heterogeneity. There are still challenges in analyzing the molecular alternations within the heterogeneous microenvironment for endocrine tumors. Recently, several proteomic, lipidomic and metabolomic platforms have been applied to the analysis of endocrine tumors to explore the cellular and molecular mechanisms of tumor genesis, progression and metastasis. In this review, we provide a comprehensive overview of spatially resolved proteomics, lipidomics and metabolomics guided by mass spectrometry imaging and spatially resolved microproteomics directed by microextraction and tandem mass spectrometry. In this regard, we will discuss different mass spectrometry imaging techniques, including secondary ion mass spectrometry, matrix-assisted laser desorption/ionization and desorption electrospray ionization. Additionally, we will highlight microextraction approaches such as laser capture microdissection and liquid microjunction extraction. With these methods, proteins can be extracted precisely from specific regions of the endocrine tumor. Finally, we compare applications of proteomic, lipidomic and metabolomic platforms in the field of endocrine tumors and outline their potentials in elucidating cellular and molecular processes involved in endocrine tumors.

Surgical strategies of complicated pheochromocytomas/paragangliomas and literature review

Pheochromocytomas (PCC)/paragangliomas (PGL) are catecholamine (CA) -secreting neuroendocrine tumors, which are known as PPGL due to their histological and pathophysiological similarities. In addition to the typical triad of paroxysmal headache, palpitation, and sweating, PPGL may also be accompanied by symptoms and signs involving multiple organs and systems such as the cardiovascular system, digestive system, endocrine system, and nervous system. Currently, surgical resection is the first choice for PPGL. Safe and effective surgical management of complicated PPGL is the goal of clinical work. In this paper, we discuss this hot issue based on complicated PPGL cases, aiming to share our experience of the surgical management strategy of PPGL.

Car accident as a trigger for reverse takotsubo-like cardiomyopathy with paraganglioma: Case report and literature review

Paraganglioma (PGL), which may cause acute Takotsubo-like cardiomyopathy (TLC), is a rare neuroendocrine neoplasm derived from various body sites. TLC has been associated with excessive catecholamine secretion and shares the same cardiac presentation with Takotsubo cardiomyopathy (TTC). We present the case of a 58-year-old male who arrived at the hospital after a car accident, reporting symptoms of chest tightness, shortness of breath, and abdominal pain after a car accident. The patient was found to have elevated troponin and severely depressed left ventricular function. Echocardiography depicted a normal contracting apex with the rest of the left ventricle being hypokinetic. Coronary computed tomography (CT) angiogram revealed mild coronary artery disease. Abdominal CT further revealed a mass on the left side of the epigastric aorta, confirmed by autopsy as a PGL.

Computerized tomography texture analysis of pheochromocytoma: relationship with hormonal and histopathological data

OBJECTIVES

Pheochromocytomas are rare tumors which can present with heterogeneous secretion profiles, clinical manifestations, and radiologic appearance. Under a histopathological point of view, they can be characterized as more or less aggressive with the Pheochromocytoma of the Adrenal gland Scaled Score (PASS) and the Grading system for Adrenal Pheochromocytoma and Paraganglioma (GAPP) score. The aim of this study is to analyze the texture analysis characteristics of pheochromocytoma and identify whether the texture analysis can yield information aiding in the diagnosis and the characterization of those tumors.

METHODS

Radiological, biochemical, and histopathological data regarding 30 consecutive patients with histologically confirmed pheochromocytoma were analyzed. Images obtained in the unenhanced, late arterial, venous, and delayed phases were used for the texture analysis.

RESULTS

Urinary epinephrine and metanephrine levels showed a significant correlation (R² = 0.946; R² = 699) in the multivariate linear model with texture features, as well as Ki-67 (R² = 0.397), PASS score (R² = 0.182), GAPP score (R² = 0.705), and cellularity showed a significant correlation (R² = 0.389). The cluster analysis based on radiomic features resulted in 2 clusters, with significative differences in terms of systolic and diastolic blood pressure values at the time of diagnosis (p = 0.025), GAPP score (4 vs 6, p = 0.05), histological pattern (1-2, p = 0.039), and comedonecrosis (0% vs 50%, p = 0.013).

CONCLUSION

In conclusion, our study provides the proof of concept for the use of texture analysis on contrast-enhanced CT images as a noninvasive, quantitative tool for helping in the characterization of the clinical, biochemical, and histopathological features of pheochromocytoma.

Composite pheochromocytoma with spindle cell sarcoma - a rare tumor of the adrenal gland: case report

Composite pheochromocytomas with a non-pheochromocytoma component stemming from an embryological origin other than the neural crest comprise a unique entity. We present a patient diagnosed with a composite pheochromocytoma with spindle cell sarcoma, which is, to our knowledge, the first case reported in the current literature. A 45-year-old female patient with elevated blood pressure had undergone adrenalectomy for clinically and radiologically diagnosed pheochromocytoma. Macroscopic examination of the specimen showed an encapsulated mass containing two nodules. One tumor was composed of large polygonal neoplastic cells with round vesicular nuclei and granular cytoplasm forming the characteristic Zellballen pattern consistent with pheochromocytoma, while the other was composed of spindle cells with hyperchromatic nuclei and prominent nucleoli, thus resembling a sarcoma. The patient was discharged on the fourth post-operative day without any complications. Even though for both tumors surgical resection is the main treatment modality, our case report aims to shed light on and discuss the etiology and management of a rarely presented composite pheochromocytoma and spindle cell sarcoma.

Commutability Assessment of Processed Human Plasma Samples for Normetanephrine and Metanephrine Measurements Based on the Candidate Reference Measurement Procedure

Background

To identify candidate external quality assessment (EQA) materials for normetanephrine and metanephrine measurements, we assessed the commutability of eight processed human plasma samples. The agreement between routine assays and the candidate reference measurement procedure (cRMP) was also evaluated.

Methods

Fifty-three clinical samples and eight processed plasma samples were prepared. The processed samples included pooled and individual plasma samples spiked with pure normetanephrine and metanephrine and non-spiked pooled and individual plasma samples. The clinical and processed samples were subjected to four routine isotope dilution tandem mass spectrometry assays and cRMP. Commutability was assessed based on two approaches recommended by the CLSI and International Federation of Clinical Chemistry (IFCC). Passing–Bablok regression and Bland–Altman analysis were used to evaluate the agreement between the routine assays and cRMP.

Results

The commutability results of the CLSI approach were better than those of the IFCC approach. For the CLSI approach, spiked individual plasma samples and spiked high-concentration pooled plasma samples were commutable for all routine assays for both analytes. The non-spiked pooled plasma sample was commutable for two out of four routine assays for metanephrine and three out of four routine assays for normetanephrine. The agreement between the routine assays and the cRMP was satisfactory, except for one routine assay showing significant bias.

Conclusions

High-concentration spiked pooled plasma samples and spiked individual plasma samples are candidate EQA materials for normetanephrine and metanephrine measurements.

Spontaneous Retroperitoneal Bleeding as a Complication of Unusual Renal Paraganglioma

Spontaneous retroperitoneal bleeding is a rare occurrence that might have catastrophic implications. We present a 58-year-old male with a 4-day history of progressively worsening left-sided flank pain due to retroperitoneal hemorrhage from a nonfunctional renal paraganglioma. Abdominal contrast CT scan was helpful in locating the tumor, estimating tumor size and extent of bleeding, visualizing the interaction between the tumor and the surroundings, and ruling out any potential metastasis; however, it lacked specificity in identifying the origin of the mass, needing histologic investigation for a conclusive diagnosis. MRI was not available at our center. We report a rare case of spontaneous retroperitoneal bleeding as a complication of an unusual nonfunctional renal paraganglioma, which was initially misdiagnosed as renal cell carcinoma but later confirmed by postoperative histopathology.

An incidental finding of retroperitoneal paraganglioma during the coronavirus disease 2019 pandemic: a case report

Background

Extra-adrenal paraganglioma of the retroperitoneum is a very rare neoplasm arising from cells of the primitive neural crest. Although paragangliomas are considered benign and are often found incidentally, they have the potential to metastasize.

Case presentation

We report the case of a 68-year-old Caucasian woman with an incidental diagnosis of retroperitoneal paraganglioma that was discovered on chest computed tomography performed for high suspicion of coronavirus disease 2019 pneumonia. The patient showed no metastasis and was successfully treated by complete surgical removal of the tumor.

Conclusion

As the diagnosis of paragangliomas is often delayed because of absent clinical symptoms, they represent a significant diagnostic challenge. Although surgery may exacerbate coronavirus disease 2019 infection, surgical resection of this tumor is prioritized, given its malignancy potential, and it must be performed as soon as no infection is detected.

Somatic Mutation Profiling in Head and Neck Paragangliomas

CONTEXT

Head and neck paragangliomas (HNPGLs) are rare neoplasms with a high degree of heritability. Paragangliomas present as polygenic diseases caused by combined alterations in multiple genes; however, many driver changes remain unknown.

OBJECTIVE

The objective of the study was to analyze somatic mutation profiles in HNPGLs.

METHODS

Whole-exome sequencing of 42 tumors and matched normal tissues obtained from Russian patients with HNPGLs was carried out. Somatic mutation profiling included variant calling and utilizing MutSig and SigProfiler packages.

RESULTS

57% of patients harbored germline and somatic variants in paraganglioma (PGL) susceptibility genes or potentially related genes. Somatic variants in novel genes were found in 17% of patients without mutations in any known PGL-related genes. The studied cohort was characterized by 6 significantly mutated genes: SDHD, BCAS4, SLC25A14, RBM3, TP53, and ASCC1, as well as 4 COSMIC single base substitutions (SBS)-96 mutational signatures (SBS5, SBS29, SBS1, and SBS7b). Tumors with germline variants specifically displayed SBS11 and SBS19, when an SBS33-specific mutational signature was identified for cases without those. Beta allele frequency analysis of copy number variations revealed loss of heterozygosity of the wild-type allele in 1 patient with germline mutation c.287-2A>G in the SDHB gene. In patients with germline mutation c.A305G in the SDHD gene, frequent potential loss of chromosome 11 was observed.

CONCLUSION

These results give an understanding of somatic changes and the mutational landscape associated with HNPGLs and are important for the identification of molecular mechanisms involved in tumor development.

A Predictive Nomogram for Early Death in Pheochromocytoma and Paraganglioma

Background

Pheochromocytoma (PHEO) and paraganglioma (PGL) are relatively rare neuroendocrine tumors. The factors affecting patients with early death remain poorly defined. We aimed to study the demographic and clinicopathologic pattern and to develop and validate a prediction model for PHEO/PGL patients with early death.

Methods

Data of 800 participants were collected from the Surveillance Epidemiology and End Results (SEER) database as a construction cohort, while data of 340 participants were selected as a validation cohort. Risk factors considered included the year of diagnosis, age at diagnosis, gender, marital status, race, insurance status, tumor type, primary location, laterality, the presence of distant metastasis. Univariate and multivariate logistic regressions were performed to determine the risk factors. R software was used to generate the nomogram. Calibration ability, discrimination ability, and decision curve analysis were analyzed in both construction and validation cohorts.

Results

PHEO and PGL patients accounted for 54.3% (N=434) and 45.7% (N=366), respectively. More than half of tumors (N=401, 50.1%) occurred in the adrenal gland, while 16.9% (N=135) were in aortic/carotid bodies. For the entire cohort, the median overall survival (OS) was 116.0 (95% CI: 101.5-130.5) months. The multivariate analysis revealed that older age (versus age younger than 31; age between 31 and 60: OR=2.03, 95% CI: 1.03-4.03, P=0.042; age older than 60: OR=5.46, 95% CI: 2.68-11.12, P&lt;0.001), female gender (versus male gender; OR=0.59, 95% CI: 0.41-0.87, P=0.007), tumor located in aortic/carotid bodies (versus tumor located in adrenal gland; OR=0.49, 95% CI: 0.27-0.87, P=0.015) and the presence of distant metastasis (versus without distant metastasis; OR=4.80, 95% CI: 3.18-7.23, P&lt;0.001) were independent risk factors of early death. The predictive nomogram included variables: age at diagnosis, gender, primary tumor location, and distant metastasis. The model had satisfactory discrimination and calibration performance: Harrell’s C statistics of the prediction model were 0.733 in the construction cohort and 0.716 in the validation cohort. The calibration analysis showed acceptable coherence between predicted probabilities and observed probabilities.

Conclusions

We developed and validated a predictive nomogram utilizing data from the SEER database with satisfactory discrimination and calibration capability which can be used for early death prediction for PHEO/PGL patients.

An Analysis of Computed Tomography Imaging Features and Predictive Factors for Postoperative Recurrence and Metastasis of Abdominal Paragangliomas

Methods

We studied 51 abdominal PGL patients at the First Affiliated Hospital of Bengbu Medical College, Tongde Hospital, and Sir Run Shaw Hospital, Hangzhou, Zhejiang Province, China, from June 2009 to May 2019. Thereafter, the clinical research data, tumor biomarkers, and CT features were compared between the aggressive PGLs and the nonaggressive PGLs using independent-samples t-tests and chi-square tests.

Results

Of the 51 cases, 43 were benign and 8 had malignant tendencies. Postoperative recurrence and metastasis were more likely to occur when the tumor diameter was >8 cm or/and the enhancement degree was not obvious. Clinical symptoms, tumor markers, sex, age, and CT image characteristics including morphology, presence of cystic degeneration, "pointed peach" sign, calcification, hemorrhage, enlarged lymph nodes, and peritumor and intratumor blood vessels were not significantly different between the two groups (p > 0.05).

Conclusion

Our findings suggest that CT features, including size >8 cm and enhancement degree, could provide important evidence to assess risk factors for aggressive PGLs.

Diagnosis and Outcome of Cardiac Paragangliomas: A Retrospective Observational Cohort Study in China

Background: Cardiac paragangliomas (CPGLs) are rare neuroendocrine tumors that are easily overlooked and difficult to diagnose. Detailed comprehensive data regarding CPGL diagnosis and outcome are lacking.

Methods: We retrospectively analyzed a cohort of 27 CPGL patients. This cohort represents the largest such cohort reported to date.

Results: The prevalence of trilogy symptoms (concurrent palpitations, hyperhidrosis, and headache) was frequent (9/27, 33.3%). Sensitivity of echocardiography and contrast-enhanced computed tomography for localization of CPGL were 81.8% and 87%, respectively. Octreotide scintigraphy showed 100% sensitivity for detecting GPCLs, while sensitivity of I¹³¹-metaiodoben-zylguanidine scintigraphy was only 32.9%. Multiple tumors were found in 29.6% of patients. Most CPGLs originated from the epicardium or root of the great vessels (92.9%) and were mostly supplied by the coronary arteries and their branches (95.7%). Twenty-four patients underwent surgical treatment. Although local invasion was present in 40.0% of patients, it did not affect long-term outcome. Mean follow-up was 6.9 ± 3.6 years. Biochemical remission was achieved in 85% of patients. The recurrence rate was 15%.

Conclusions: Manifestations of CPGLs are non-specific and they can be difficult to detect on imaging examinations. Octreotide scintigraphy should be performed in patients with suspected paragangliomas to screen for multiple lesions. Surgical resection of CPGLs can achieve symptom relief and biochemical remission.

A rare case of multiple paragangliomas in the head and neck, retroperitoneum and duodenum: A case report and review of the literature

Pheochromocytomas and paragangliomas (PGLs) are rare non-epithelial neuroendocrine neoplasms of the adrenal medulla and extra-adrenal paraganglia respectively. Duodenal PGL is quite rare and there are only two previous reports. Herein, we report a case of multiple catecholamines (CAs)-producing PGLs in the middle ear, retroperitoneum, and duodenum, and review the literature of duodenal PGLs. A 40-year-old man complained right-ear hearing loss, and an intracranial tumor was suspected. Magnetic resonance imaging of the head revealed a 3-cm mass at the right transvenous foramen, which was surgically resected following preoperative embolization. The pathological diagnosis was a sympathetic PGL of the right middle ear. Six years later, family history of PGL with germline mutation of succinate dehydrogenase complex iron sulfur subunit B, SDHB: c.268C>T (p.Arg90Ter) was clarified. The patient had elevated levels of plasma and urine CAs again. Abdominal computed tomography scanning revealed two retroperitoneal tumors measuring 30-mm at the anterior left renal vein and 13-mm at near the ligament of Treitz. The larger tumor was laparoscopically resected, but the smaller tumor was not identified by laparoscopy. After the operation, the patient remained hypertensive, and additional imaging tests suggested a tumor localized in the duodenum. The surgically resected tumor was confirmed to be a duodenal PGL. After that, the patient remained hypertension free, and urinary levels of noradrenaline and normetanephrine decreased to normal values. No recurrence or metastasis has been found at 1 year after the second operation. CAs secretion from PGLs in unexpected location, like the duodenum of our patient, may be overlooked and leads to a hypertensive crisis. In such cases, comprehensive evaluation including genetic testing, fluorodeoxyglucose-positron emission tomography scanning, and measurement of CAs will be useful for detecting PGLs. Most previous reports on duodenal PGL were gangliocytic PGL which has been renamed composite gangliocytoma/neuroma and neuroendocrine tumor, and defined the different tumor from duodenal PGL. We reviewed and discussed duodenal PGLs in addition to multiple PGLs associated with SDHB mutation.

Bladder paraganglioma: CT and MR imaging characteristics in 16 patients

Background

Bladder paraganglioma (BPG) is a rare extra-adrenal pheochromocytoma with variable symptoms and easy to be misdiagnosed and mishandled. The aim of the study was to document the imaging features of BPG using computed tomography (CT) and magnetic resonance imaging (MRI).

Patients and methods

We retrospectively enrolled consecutive patients with pathology-proven BPG, who underwent CT or MRI examinations before surgery between October 2009 and October 2017. The clinical characteristics, CT, and MRI features of the patients were described and analysed.

Results

A total of 16 patients with 16 bladder tumours (median age 51 years, 9 females) were included. Among them, 13 patients underwent CT examinations and eight patients underwent MRI examinations preoperatively. Tumour diameters ranged from 1.6−5.4 cm. Most of the tumours grew into the bladder cavity (n = 11) with oval shapes (n = 10) and well-defined margins (n = 14). Intratumour cystic degeneration or necrosis (n = 2) was observed. Two lesions showed peripheral tissue invasion, suggesting malignant BPGs. All 13 lesions imaged with CT exhibited slight hypoattenuation and moderate to marked enhancement. Compared to the gluteus maximus, all lesions showed slight h yperintensity in T2-weighted images, hyperintensity on diffusion-weighted images (DWI), hypointensity on apparent diffusion coefficient maps, hyperintensity on T1-weighted images and a “fast in and slow out” enhanced pattern on contrast-enhanced MRI images.

Conclusions

BPGs are mostly oval-shaped, broadly-based and hypervascular bladder tumours with hypoattenuation on non-contrast CT, T2 hyperintensity, slight T1 hyperintensity compared to the muscle, marked restricted diffusion on DWI. Peripheral tissue invasion can suggest malignancy of the BPGs. All of these features contribute to preoperative decision-making.

Emergent transcatheter arterial embolization to control critical blood pressure fluctuation associated with hypercatecholaminemic crisis in a patient with an unruptured retroperitoneal paraganglioma

Pheochromocytoma/paraganglioma (PPGL)-related hypercatecholaminemic crisis is a rare lethal condition caused by uncontrolled catecholamine secretion, occasionally leading to critical fluctuation in blood pressure (BP). Emergent transcatheter arterial embolization (TAE) has been employed for spontaneous PPGL rupture, but never, to our knowledge, for critical fluctuation in BP associated with PPGL-related hypercatecholaminemic crisis. We describe here our experience utilizing this method to control critical fluctuation in BP associated with this crisis in a 44-year-old man with an unruptured retroperitoneal paraganglioma. The patient experienced sudden severe left abdominal pain and came to our emergency department, where he exhibited severe fluctuation in BP and underwent laboratory testing that showed hypercatecholaminuria and computed tomography (CT) that revealed a left retroperitoneal tumor with no apparent intra- or retroperitoneal hematoma. We performed emergent TAE from the left inferior phrenic artery using gelatin sponge, which stabilized his BP and relieved his abdominal pain. Histologic examination following elective surgical resection of the tumor confirmed our diagnosis of unruptured retroperitoneal paraganglioma. We believe that TAE represents an important option for the emergent treatment of the critical BP fluctuation associated with PPGL-related hypercatecholaminemic crisis.

VEGF-A/VEGF-B/VEGF-C expressions in non-hereditary, non-metastatic phaeochromocytoma

Vascular endothelial growth factor (VEGF) is important in pathogenesis of different cancers. The aim of this study is to investigate the relationships between different VEGFs and clinicopathological factors in patients with phaeochromocytomas. Twenty patients (10 men; 10 women) with non-hereditary, non-metastatic phaeochromocytomas were examined for VEGF mRNA expressions by polymerase chain reaction. The expressions were correlated with the clinical and pathological factors of the patients. In addition, mouse double minute 2 (MDM2) expression in these tumours were studied by immunohistochemistry. High expressions of VEGF-A, VEGF-B, and VEGF-C mRNA were detected in 11 (55%), 9 (45%), and 9 (45%) of the tumours respectively. High expression of VEGF-A in phaeochromocytomas was significantly correlated with the tumour size (p=0.025) but did not correlate with patients' age, gender, and tumour laterality. Besides, there was a trend of VEGF-A expression correlated with MDM2 expression (p=0.064). On the other hand, expressions of VEGF-B and VEGF-C were not significantly correlated with tumour size, patients' age, gender, tumour laterality, and MDM2 expression. In addition, high expressions of VEGF-B and VEGF-A were associated with increase of tumour size (p=0.042). Co-expression of different VEGFs did not correlate with MDM2 expression. To conclude, there is a role for VEGF-A/VEGF-B/VEGF-C in the pathogenesis of non-hereditary, non-metastatic phaeochromocytomas.

Neurological Complications of Endocrine Emergencies

PURPOSE OF REVIEW

Endocrine disorders are the result of insufficient or excessive hormonal production. The clinical course is long, and the manifestations are nonspecific due to the systemic effect of hormones across many organs and systems including the nervous system. This is a narrative review of the recent evidence of the diagnosis and treatment approach of these medical and neurological emergencies.

RECENT FINDINGS

With the possible exception of diabetic ketoacidosis, hyperosmolar hyperglycemic state, and hypoglycemia, endocrinological emergencies are complex, uncommon yet life-threatening conditions with protean and often nonspecific early clinical signs. They frequently are the first manifestation of the endocrine derangement. The systemic effects of hormones extend to the nervous system and as such, these conditions can present with neurological complications manifested, in most cases, by a diffuse dysfunction of the brain in the form of encephalopathy, delirium, seizures, and coma; or specific and peculiar syndromes such as hemichorea, hemiballism, and epilepsia partialis continua. The severity of these conditions often necessitates management in the intensive care unit requiring substantial supportive care in addition to specific targeted therapy to correct the hormonal metabolic abnormalities while at the same time blocking hormonal activity, in cases of excessive function, or supplementing hormonal deficiencies. Endocrine emergencies and their neurological complications are infrequent. The major challenge for most is early recognition. Their morbidity and mortality are high and their diagnosis requires high index of suspicion. The neurological complication most often improves with the correction of the metabolic derangement and their acuity and severity require admission to the intensive care unit.

Plasma Metabolome Profiling for the Diagnosis of Catecholamine Producing Tumors

CONTEXT

Pheochromocytomas and paragangliomas (PPGL) cause catecholamine excess leading to a characteristic clinical phenotype. Intra-individual changes at metabolome level have been described after surgical PPGL removal. The value of metabolomics for the diagnosis of PPGL has not been studied yet.

OBJECTIVE

Evaluation of quantitative metabolomics as a diagnostic tool for PPGL.

DESIGN

Targeted metabolomics by liquid chromatography-tandem mass spectrometry of plasma specimens and statistical modeling using ML-based feature selection approaches in a clinically well characterized cohort study.

PATIENTS

Prospectively enrolled patients (n=36, 17 female) from the Prospective Monoamine-producing Tumor Study (PMT) with hormonally active PPGL and 36 matched controls in whom PPGL was rigorously excluded.

RESULTS

Among 188 measured metabolites, only without considering false discovery rate, 4 exhibited statistically significant differences between patients with PPGL and controls (histidine p=0.004, threonine p=0.008, lyso PC a C28:0 p=0.044, sum of hexoses p=0.018). Weak, but significant correlations for histidine, threonine and lyso PC a C28:0 with total urine catecholamine levels were identified. Only the sum of hexoses (reflecting glucose) showed significant correlations with plasma metanephrines.By using ML-based feature selection approaches, we identified diagnostic signatures which all exhibited low accuracy and sensitivity. The best predictive value (sensitivity 87.5%, accuracy 67.3%) was obtained by using Gradient Boosting Machine Modelling.

CONCLUSIONS

The diabetogenic effect of catecholamine excess dominates the plasma metabolome in PPGL patients. While curative surgery for PPGL led to normalization of catecholamine-induced alterations of metabolomics in individual patients, plasma metabolomics are not useful for diagnostic purposes, most likely due to inter-individual variability.

Pheochromocytoma: A three-decade clinical experience in a multicenter study

OBJECTIVE

To analyze the clinical and analytical features, diagnostic tests, therapies, and outcomes of pheochromocytoma (PCC).

DESIGN AND METHODS

A multicenter retrospective study in surgically treated patients with PCC followed in 3 Spanish tertiary referral hospitals.

RESULTS

A total of 106 patients (61 [57.5%] women, mean age 52.3 ± 14.8 years) were evaluated. At diagnosis, PCC was symptomatic in 62% and sporadic in 83%. Patients with familial PCC were significantly younger than those with sporadic disease (40.8 ± 14.2 years vs. 54.5 ± 13.9 years, p<.001). Familial PCCs were more frequently associated with MEN2A (n=8). Levels of 24-h urinary fractionated metanephrines were positively related to tumor size. The maximum tumor diameter was 4.3cm (3-6cm); 27.7% of the patients had tumors ≥6cm. Incidental PCCs were significantly smaller than symptomatic PCCs (3.4cm [2.4-5.0cm] vs. 5.6cm [4.0-7.0cm], p<.001). Scintigraphy by 123I-metaiodobenzylguanidine showed a high sensitivity (81.9%). Preoperative alpha blockade with phenoxybenzamine was used in 93.6% and doxazosin in the rest. Laparoscopic surgery was used in 2/3 of the patients, with a low conversion (1.9%) to open surgery. Perioperative complications appeared in approximately 20% of patients, mainly hypertensive crisis (9.4%). Recurrent disease appeared in 10%, and malignant PCC was uncommon (6.3%).

CONCLUSIONS

PCCs surgically treated in Spain are usually large, symptomatic, and sporadic tumors diagnosed around the sixth decade of life. Hereditary PCC is usually associated with MEN2A. The main type of surgical technique used is laparoscopic surgery, and the prevalence of metastatic PCC is low.

An update on adult forms of hereditary pheochromocytomas and paragangliomas

PURPOSE OF REVIEW

Pheochromocytomas and paragangliomas (PPGL) display a strong genetic determinism with 40% of inherited forms. The purpose of this review is to provide an update on current knowledge on adult forms of hereditary PPGL and their management.

RECENT FINDINGS

PPGL are genetically-driven in 70% of cases, with germline and/or somatic mutations identified in more than 20 genes. Although eight new susceptibility genes have recently emerged, mutations on SDHx genes remain the most frequent. In addition to SDHB, mutations in SLC25A11, FH and MDH2 may predispose to a metastatic disease and somatic alterations including TERT and ATRX mutations, and the differential expression on noncoding RNAs are also associated with the occurrence of metastases.The biochemical diagnosis remains the mainstay of functional PPGL and does not differ between hereditary PPGL while the choice of the best nuclear imaging approach is dictated by the tumor type and can be influenced by the presence of a germline mutation (18F-DOPA PET/CT for cluster 2 mutation and Ga-DOTATATE PET/CT for cluster 1 mutation).

SUMMARY

A systematic genetic testing and counselling is recommended for all PPGL patients and should lead to conservative surgery and an adapted follow up, in case of hereditary form.

Pheochromocytoma and Paraganglioma: From Treatment to Follow-up

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors arising from chromaffin cells in the adrenal medulla, sympathetic or parasympathetic ganglia. Currently, the only curative treatment option of pheochromocytomas/paraganglioma (PPGL) is surgical resection. Surgery aims to eliminate both risks of hypersecretion and tumor growth. The consequences of hypersecretion should be carefully controlled with medical therapy before and during the surgery. Postoperative major complications are hypotension and rebound hypoglycemia, and patients should be followed closely for 24-48 hours. The choice of surgical approach is determined based on multiple factors, including germline genetic test results, the size of the tumor, body mass index, surgeon's experience, and the likelihood of malignancy. Primary tumor resection does not completely eliminate the risk of tumor persistence and recurrence. Therefore, all patients with PPGL who are surgically treated should be followed for at least 10 years for recurrent disease and new tumor formation. Although surgical resection is the only curative treatment for PPGLs, surgical treatment is palliative except for resectable locoregional metastases in metastatic disease or for isolated distant metastases. The purpose of palliative treatment is to reduce hormone secretion and prevent metastasis-related complications in a critical anatomical location Combined and alfa;- and beta- adrenergic blockade is usually applied in patients with PPGL preoperatively. Some patients may present with pheochromocytoma multisystem crisis, which is a life-threatening condition that can involve cardiovascular, pulmonary, neurological, gastrointestinal, renal, hepatic and metabolic systems. Pheochromocytoma crisis may be spontaneous or may present with the tumor manipulation, trauma, corticosteroids, beta-blockers, anesthetic drugs, and the stimulation of non-adrenal surgical stress. These patients should be considered as medical emergencies rather than surgical emergencies. In this review, it was aimed to evaluate the pre-, per and post-operative management, curative and palliative surgical management, and postoperative outcomes and follow-up of the patients with PPGLs.

Pheochromocytoma: A three-decade clinical experience in a multicenter study

OBJECTIVE

To analyze the clinical and analytical features, diagnostic tests, therapies, and outcomes of pheochromocytoma (PCC).

DESIGN AND METHODS

A multicenter retrospective study in surgically treated patients with PCC followed in 3 Spanish tertiary referral hospitals.

RESULTS

A total of 106 patients (61 [57.5%] women, mean age 52.3 ± 14.8 years) were evaluated. At diagnosis, PCC was symptomatic in 62% and sporadic in 83%. Patients with familial PCC were significantly younger than those with sporadic disease (40.8 ± 14.2 years vs 54.5 ± 13.9 years, p < .001). Familial PCCs were more frequently associated with MEN2A (n = 8). Levels of 24-h urinary fractionated metanephrines were positively related to tumor size. The maximum tumor diameter was 4.3 cm (3-6 cm); 27.7% of the patients had tumors ≥6 cm. Incidental PCCs were significantly smaller than symptomatic PCCs (3.4 cm [2.4-5.0 cm] vs 5.6 cm [4.0-7.0 cm], p < .001). Scintigraphy by ¹²³I-metaiodobenzylguanidine showed a high sensitivity (81.9%). Preoperative alpha blockade with phenoxybenzamine was used in 93.6% and doxazosin in the rest. Laparoscopic surgery was used in 2/3 of the patients, with a low conversion (1.9%) to open surgery. Perioperative complications appeared in approximately 20% of patients, mainly hypertensive crisis (9.4%). Recurrent disease appeared in 10%, and malignant PCC was uncommon (6.3%).

CONCLUSIONS

PCCs surgically treated in Spain are usually large, symptomatic, and sporadic tumors diagnosed around the sixth decade of life. Hereditary PCC is usually associated with MEN2A. The main type of surgical technique used is laparoscopic surgery, and the prevalence of metastatic PCC is low.

Pheochromocytoma and Paraganglioma: From Clinical Findings to Diagnosis

The majority of pheochromocytoma (PCC) and paraganglioma (PGL) are endocrine active tumors, and they cause clinical symptoms by secreting excess one or more catecholamines (epinephrine, norepinephrine, and dopamine) and their inactive metabolites (metanephrine, normetanephrine, 3-metoxythromine). Although signs and symptoms regarding excess catecholamine often develop in PCC and PGL (PPGL), non-functional PPGLs may present with local compression symptoms. Persistent, sometimes worsening hypertension is the most common finding and occurs in 80-90% of the patients. Classically defined symptom triad; headache, sweating and palpitations are seen in only 25% of the patients with PCC. The difference of clinical symptoms may be related to the tumor secretion, epinephrine or norepinephrine. All patients with signs and symptoms suggestive of catecholamine excess should be screened by biochemical tests regardless of whether they have hypertension or not. Not all patients with newly diagnosed hypertension need to be screened, but only patients with additional tips for catecholamine excess should be screened. Approximately 20% of the PPGLs are diagnosed in childhood, and the male/female ratio is 2/1. 60-90% of pediatric patients present with hypertension. PPGL in pregnancy is rare, and the estimated incidence ranges between 1/15000-1/54000. Although early diagnosis is the most important factor in preventing mortality, diagnosis is not as easy as it is a rare condition. Hypertension is a common complication in pregnancy, occurring in 5-10%. Computed tomography should not be used as the imaging method during pregnancy; the first choice is magnetic resonance imaging with gadolinium or without contrast. Plasma free metanephrine or 24-hour urinary fractionated metanephrine level is recommended as a screening test for the diagnosis of PPGL in the Endocrine Society Clinical Practice Guideline. In suspicious situations, tests should be repeated. Since 40% of these patients have germline mutations, genetic tests are recommended for all patients with PPGL regardless of family history and age. Preoperative knowledge of germline mutations affects the surgical approach and the extent of adrenalectomy. After the biochemical diagnosis is made in PPGL, the tumor is localized with imaging methods to make the operation plan. In this review, we aimed to evaluate the clinical findings, diagnostic tests, and imaging studies for tumor localization in PPGL.

Pheochromocytoma and Paraganglioma: From Epidemiology to Clinical Findings

Pheochromocytomas (PCC) and paragangliomas (PGL) are rare neuroendocrine tumors. Pheochromocytomas arise from chromaffin cells in the adrenal medulla, and PGLs arise from chromaffin cells in the ganglia of the autonomic nervous system. Paragangliomas originate from sympathetic or parasympathetic ganglia in the abdomen, thorax, and pelvis. The majority of PCC and sympathetic PGL are endocrine active tumors causing clinical symptoms by secreting excess catecholamines (norepinephrine, epinephrine, dopamine) and their metabolites. The incidence of PCC and PGL ranges between 2 and 8 per million, with a prevalence between 1:2500 and 1:6500. It peaks between the 3rd and 5th decades of life, and approximately 20% of cases are pediatric patients. The prevalence among patients with hypertension in outpatient clinic ranges between 0.1-0.6% in adults and between 2-4.5% in the pediatric age group. 10-49% of these tumors is detected incidentally in imaging techniques performed for other reasons. However, 4-8% of adrenal incidentalomas are PCCs. Of these neuroendocrine tumors, 80-85% are PCCs and 15-20% are PGLs. Up to 40% of patients with PCC and PGL has disease-specific germline mutations and the situation is hereditary. Of 60% of the remaining sporadic patients, at least 1/3 has a somatic mutation in predisposing genes. 8% of the sporadic cases, 20-75% of the hereditary cases, 5% of the bilateral, adrenal cases, and 33% of the extra-adrenal cases at first presentation are metastatic. Although PCCs and PGLs have scoring systems for histological evaluation of the primary tumor, it is not possible to diagnose whether the tumor is malignant since there is no histological system approved for the biological aggressiveness of this tumor group. Metastasis is defined as the presence of chromaffin tissue in non-chromaffin organs, such as lymph nodes, liver, lungs and bone. Although most of the PCC and PGL are benign, the metastatic disease may develop in 15-17%. Metastatic disease is reported between 2-25% in PCCs and 2.4-60% in PGLs. The TNM staging system of the American Joint Committee on Cancer (AJCC) was developed to predict the prognosis, based on the specific anatomical features of the primary tumor and the occurrence of metastasis.